Reciprocating pneumatic actuator for tools



Jan. 18 1955 L. c. MILLER RECIPROCATING PNEUMATIC ACTUATOR FOR TOQLS Filed Sept. 15. 1950 2 Sheets-Sheet l F? C'- Ill/(LE1? (EON/0 5 JNVENTOR.

w wuw QITQQNEIJS United States Patent RECIPROCATING PNEUMATIC ACTUATOR FOR TOOLS Leonidas C. Miller, Los Angeles, Calif.

Application September 15, 1950, Serial No. 185,120

18 Claims. (Cl. 121-38) This invention relates to a fluid driven actuator and is part1cularly directed to improvements in a pneumatic afituator for operating a tool such as, for example, a s ear.

Among the objects of this invention are to provide a light-weight tool and actuator assembly adapted to be grasped in one hand and supported and operated thereby, to provide a device of this type in which a manually graspable section of the device is positioned between the tool support and the power cylinder, to provide a novel form of air system for applying power to one stroke of the tool and for returning the tool to its initial position without the use of springs, and to provide a novel form of valve assembly which is demountable as a unit from the manually graspable body portion of the device.

Other and more detailed objects and advantages will appear more fully hereinafter.

in the drawings:

Figure 1 is a plan view showing a preferred embodiment of my invention.

Figure 2 is a side elevation thereof partly broken away.

Figure 3 is a sectional elevation on an enlarged scale taken substantially on the line 3-3 as shown in Figure 1.

Figure 4 is a longitudinal sectional view partly broken away showing details of the valve assembly, the valve being in open position.

Figure 5 is a sectional view similar to Figure 4 showing the valve shifted to closed position.

Figures 6, 7 and 8 are transverse sectional views taken substantially on the lines 66, 7-7, and 88 respectively as shown in Figure 3.

Referring to the drawings, the device includes a manually graspable body portion 10, a power cylinder assembly 11, a control valve mechanism 12, and a power driven tool generally designated 13. The general plan of operation contemplates that fluid under pressure delivered by the supply line 14 causes a piston within the power cylinder assembly 11 to reciprocate and thereby operate the tool 13. This operation is under the control of the valve assembly 12 so that when the operating handle 15 is depressed the tool is actuated in one direction, and when the handle 15 is released the tool is actuated in the other direction.

The body comprises an elongated section having an axial bore 16 extending longitudinally therethrough. One end of the body is formed with a circular flange 17 having a cylindrical projection 18 extending axially therefrom. The other end of the body is provided with a plurality of upstanding lugs 19 separated by a pair of axially extending slots 20. The tool 13 is provided with parallel support bars 21 which extend into the slots 20 between the lugs 19. These support bars 21 are fixed relative to the lugs 19 by means of clamping bolts 22. The cylindrical projection 18 is provided with external threads 23 to receive the internal threads 24 of the shell 25. The flange 17, projection 18 and shell 25 form a part of the power cylinder assembly 11.

The shell 25 is internally threaded at 26 to receive the external thread 27 on the end closure 28. The closure 28 is provided with a central boss 29 which is threaded at 30 to receive the threaded bushing 31. A look nut 32 serves to anchor the bushing 31 with respect to the end closure 28. A fitting 33 serves to connect the pressure fluid supply line 14 with the bushing 31. This connection is accomplished by means of interengaging threads 34 and seal ring 35. A stationary tube 36 is fixed in the bushing 31 by any convenient means and extends axially of the power cylinder assembly. 11. Fluid pressure supplied 2,699,756 Patented Jan. 18, 1955 ICC from the line 14 passes directly into the interior of the tube 36 through the central passage 37 in the bushing 31. A piston 38 is provided with a sealing ring 39 which slides in sealing engagement with the inner cylindrical surface 40 of the shell 25. The piston rod 41 is enlarged at one end and is provided with a shoulder 42. The piston 38 is fixed on the piston rod 41 and clamped against the shoulder 42 by means of a clamping nut 43.

The enlarged end of the piston rod 41 is provided with an axially extending cylindrical bore 44, and the annular seal plug 45 which is fixed on the end of the stationary tube 36 is slidably received within this bore 44. A seal ring 46 is provided to prevent leakage. The seal plug 45 acts as a piston within the cylindrical bore 44. The piston rod 41 reciprocates within the cylindrical bushing 47 which is fixed within the bore 16 in the body member. The forward end of the piston rod is provided with a hardened sleeve 48 which fits within the bushing 47. The piston rod is provided with internal threads 49 at its forward end to receive an externally threaded actuating rod 50. A lock nut 51 secures the actuating rod in selected position with respect to the piston rod 41.

The piston 38 serves to divide the power cylinder assembly into a forward chamber 52 and a rear chamber 53. Means are provided for alternately pressurizing and venting the forward chamber 52, and as shown in the drawings this means includes the detachable valve assembly unit 12. This unit 12 includes a housing 54 provided with a cylindrical bore 55. The housing 54 is rounded on its upper portion, and its lower edge 56 is formed in an axially extending plane as shown clearly in Figures 6-8. The housing 54 and body 10 cooperate to provide a handle grip which may be grasped manually in one hand for supporting the device. The flat surface 56 on the housing is machined to fit the corresponding flat surface 57 provided on the body 10. The ends of the housing 54 adjacent the lower horizontal surface 56 are bevelled as shown at 58 and 59. The bevelled surface 58 is received within the corresponding notch 60 provided on the body 10 and the bevelled surface 59 is engaged by the corre sponding bevelled surface 61 provided on the lug 62. The lug 62 is anchored to the body 10 by means of the threaded element 63. From this description it will be understood that the valve housing may be disassembled from the body by first removing the lug 62, sliding the valve assembly 12 toward the power cylinder assembly 11 to disconnect the bevelled surfaces 58 and 60, and then lifting the valve assembly 12 radially away from the body 10. Assembly of the parts is accomplished in the inverse order. The ends of the housing 54 may be grooved as shown at 64 for reception of the dowels 65 secured on the body 10.

A plurality of lateral ports are provided in the housing 54, and each of these ports extends from the axial bore 55 downward through the horizontal surface 56. The fluid inlet port is designated 66, the delivery port for delivering fluid to the chamber 52 is designated 67, and the vent port for exhausting fluid from the chamber 52 is designated 68. Each of these ports communicates with an aligned corresponding port provided in the body 10. Thus port 66 is aligned with port 69, port 67 is aligned with port 70, and port 68 is aligned with port 71. A seal ring 72 may be provided at the junction of each of the ports to prevent leakage.

The port 69 in the body 10 communicates with a lateral opening 73 provided in the guide bushing 47. The side opening 73 in turn communicates with the annular space 74 provided by the externally grooved portion 75 of the piston 41. Seal rings 76 are provided on the piston on opposite sides of the grooved portion 75 to prevent leakage. A plurality of lateral openings 77 are provided in the piston 41 establishing communication between the central bore 78 in the piston 41 and the annular space 74. The central bore 78 communicates with the bore 44 in the piston by way of the intermediate connecting bore 79. From this description it will be understood that fluid pressure delivered into the bore 44 by the stationary tube 36 passes inward through bores 79 and 78 and through lateral ports 77 into the annular space 74. The fluid pressure then passes outward through side opening 73 in guide bushing 77 and then passes through aligned ports 69 and 66 into the central bore 55 in the valve housing 54 Longitudinal passage 97 in the body communicates b'tweeu'the' ehamufszsfiduheiaierar port "'7 0. Longitudinal passage 98 in the-body 10 connects the lateral vent port 71 to atmosphere.

- A plurality of l stationary annular elements is provided within the bdrefiiof-theyalve ousing54. These elenieiits preferably comprise three or'ted rings 80,*81{and 82. -The'-inn'er and outer rings-=80 and 82' are provided witha single' 'sealirig' 'ringi83 engaging the 'bore"55, While the centrah's'ealing ring 81" isprovided with"axially spaced sealing rings84" engaging thece'nt-ralbore 55. A lateral port 85 in "thekirig 32 c'omriiunicates'-with the housing port 68. Similarly, a'lat'e'ral port 86 in the ring 80cornrri iiiiic'ateswi'th 'the'housing port"66. -"A ce'ntralpo'rt 87 in the 'ce'nt'ral ring 81 "communicates with the 'housing port "67. Afpair of retainer rings 88' aremduht'eddn grooves 'proVided"=in' the valveho'using' 54 'andser've* to prevent axiahinov'einent of' the rings 80, 81 and 82.

{AnaXiallyniovable valve elemenf89 is positioned withinther'ings"80, s1 and 82. This element 89 com prises es's'eritially apairofsp'o'ol portions" 90 and 91join'ed e'rid-to end' andoperable asa unit. Threespace'd sealing rings 1j00,"10 1 and "102 ar'emounted on'the' movable eleine'nt89,fand these'sealing rings engagewithincylindrical rand portisss los; 104;105'and106'which are formed by 'the i'nt'einalfbores "of the individual stationary rings 80;81 and"82. Whenthe'movable valve'eremenrw is inthe"po'sition"showninFigu're'4 thedelivery port 67 is"pl'aced'in' communicatio with the vent port"68, while the iijlet port 66"isclosed 'offby' Contact of the seals 100 an'mlor' with" 'the lands 103 and 164' "on' the "stationary anriulaf'rings 80 and? 81. When'the"mova ble' valve 'ele- In'entSTisf's'hiftd' to 'thepsitio'n shownin' Figure" 5 "the i'rilet'port 66 is'blaced inwn'ifimnnicaticsn with the delivery port 67 'while' the vent port' 68 is closed off'by means'of the eem-acmrseals' 102 'and92" with the'lands' 105 and 106 enthestatienary'rifigsgrand 82. Means are p vided'for' shifting the'valve"elemenf 89 gnany betweem the" position shown "in Figure 4- and Fi'gu'r'e"5. As'shown'in'the' drawings; this' means includes the"ope' rating' lever "whichfis connected' to the 'valve f ifrgf54 by "means" of pivot 93. A hardened insert 94 on heleveren'ga'ges'a' steel ball 95 secured to one endef the other'endbf the" 'le'ment 89am! thelug 62. The sprin 96"se'rves to" return 'the'element "8? to' the open position showri'iri Figure 4"when the operator (nbtshown) reiesserthe'a eratingievems.

"Wherfthd o erating" lever 15 is in the position shown iri Figiires 1 4, 'fiuid pressure is"blocked off by "the engagemeht of'the seals 'lllfl and 101 with stationary contact riii'gS SO and'SI sothat no pressure is applied to "the ch amber 62fbut' ori the contrary this chamber is vented to atinosphere 'thiough passages '97 and- 98.

When the operating lever 15 is manually depressed-the movable valve element 89'is shifted tothe rightasViewed inthe drawings to-the;position shown in' Figure 5. -In this position ofthe valve element, fluid nndergpressure; passes through inletport 66 and out-throngh=delivery-port;7 into the 'ali'gned body' port 70 and' into thepas'sageway 97 to -the-eharnbei; 52. Fluid under; pressure is thus; applied against-theleftside ofthe piston38 as viewed'in Figure 3. A sealring 112 may be provided toprevent "escape of pressure along the threads 23e 24. --Thepiston 38 moves to-the right-because the effective area -of the forward chamber 52 is.-greater than the effective cross-section area of the bore 44; The unit pressure Within the bore- 44 is approXimat'elythe-same as theunit' pressure Within 'the forWard 'chamberSZ, but since the ePr'ective-areaof the latter is cOnsiderabIy: greaterthe piston -moves to the righton its power 'stroke. Whenthe operatinglever 15 of'the control valve assembly 12- is reieased the forward chamber-Slip ventedtoatmosphere through" passageways 97 'and 98., The 'sameunit pressure 'withiutheb'ore '44 then moves the; piston'38 back 'to its initial position on the return stroke.

a In'orderto accomplish rapid venting of the rear chamber 53"Iandrapid 'repressuring to. prevent sluggishness on-the-'return stroke; {prefer to provide -a*sm'all ble'ed' port 110 extending thr'ough the wall of the stationary tube="-36, and I further. provide a=plurality of ports 111 extendingthroughthe Wall of the'end' closure= '2 8.. When the piston-" 38 moves to the right-as vviewed in Figure- 3 air pressure"within the rear chamber 53 i exhausted to the left the rear chamber 53 is repressurized by air from the bleed port 110. 'lihe bleed port 110 is so small in comparison with the areaof ports 111 that the pressure in the rear chamber 53 does not build up above atmosphclelric pressure except when the piston 38 moves to the rig t. I

In the particular embodiment of my invention illustrated' in the drawingslthebore 44':is"larger. in diameter than the inner diameterlot-ltheibushing 47, but these relative dimensions are illustrative only and the bore 44 could be inade "smallen if desired.

A resilient cushion or bumper 113 may be provided withiirthe power cylinder assembly 11' andmounted'on the end closure--28. :This-bumper-may be formed of natural or synthetic riibber'and acts to cushion the deceleration of the piston 38 at the end of its power stroke. The piston 38 engages the rubber bumper 113 in direct G'Ofltil'CL While" the*pneumatic actuator as described above-may be used in' connection -with any one -0f a'-;number=of different types of tools, I have chosen to illustrateit in GOilXT G iOnWlih =a fpllililflg shear. This-shear designated 13 inclutie'sthe stationary b'a-rs 2i which carry the" pivot bolt114 at-theirouterends; One ofithe-bars 21 is-provided 'ith astationary:shear blade 115. A mov'able shear'olade 116 is pivotedon- "the-bolt 114 between the ba-rs"-21 andjprov-ided with aradially extending-crank arm '1'17. Alibk 118 is pivotally connected tofthe'crank armi 'lli-at 9fl-and-'is' pivotally connectedat 120-to .the actuatingrod 5%). As described above this" actuating'rod Ell-is direct-lyfconnected to the piston rod 41. When the piston'rod 341 is eXtendedl'the movable shear blade 116 is rnove'd' 'totheposition shOWn in" "Figure 2. When the piston rod is restricted on the-power stroke the link 1-18 moves the blade 116 toward the blade- 115;"as'will be readily understood. Since" the movable shear blade-116 is located between the bars 21- it 'is' centrally "positioned with resp'ectfto the' piston rod4liandt'link 118. 'No' offset is present and hence" the force l on' thej power stroke does norsubject any of the partsto" bending action. A counterbore '121'is'T'provided" at-the forwerd end or" the body '10 to' "provide ciearan'ce for the nut 51 on the power stroke.

A-movablestop 122 may be mounted onthe support bars 21 so'asto limit the'op'ening'movement of.the shear blade 116-when desired. "This stop 122 may bemov'ecl along. the horizontal-slots -123,-providedinthel-barsi' 21 so thatin one position it is engaged byithe lug. 124 provided on. theshearbiade116. .If it is-desired to havelthe=movable shear blade 116 move-through its maximum-Marc of travel-the step 122 is; shifted tothe position shown .in

' Figurel so that it is-clear of :the path. ofhtravelof-Lthe The ;si-Ze and shape ofthe body r'iii: is such that itmay be readilyagrasped in -the .palm ofathef. hand ofan operator and so-thatthe pperating lever 15 maybe moved by theinden and medial fingers. A squeezing action of means'at-the otherend of the :body

manual these gfingers depresses; the "operating -lever and; causestne movable shear -blade 116;: to 1 :move v through its; power stroke. When the fingers oi 'the operatorare rel'aXed,'-the return 1 spring- 96 moves:the operat-ingslever back to :its initial posit-ion-andthe-'movable shear blade-1.11618 .re-

mounted on: and torming a-part ofi said cent .lf grip; porof thebody;and having aan axiallyextendm' movable valve; elernent mountedF Withint-he outer surf-ac; of: the

grip portion, they'p'ower"cylinder: assembly including a piston unounted for 're'ciproc'ation within vthe shell --and pen position. A la ter lly. extending 1111 .125

raspcdby atn {operatorwhereby 'the actuator may be supported:by one hand acontro'l valve'assembly '5 having a piston rod extending axially through the body, means for connecting the piston rod to actuate the tool, means for delivering a fluid under pressure to the control valve assembly, and passage means in the body for delivering fluid under pressure from the control valve assembly to said power cylinder assembly.

2. In a portable pneumatic actuator for a tool, the combination of: a body, a power cylinder assembly ineluding a cylindrical shell, a cylindrical extension at one end of the body for connecting the body to the shell, means at the other end of the body for releasably connecting said body to a tool, the body having an axially extending central grip portion intermediate its ends shaped to be manually grasped by an operator whereby the actuator may be supported by one hand, a control valve assembly removably mounted on and forming a part of said central grip portion of the body and having an axially extending movable valve element mounted within the outer surface of the grip portion, the power cylinder assembly including a piston mounted for reciprocation within the shell and having a piston rod extending axially through the body, means for connecting the piston rod to actuate the tool, means for delivering air pressure to the control valve assembly, and passage means in the body for delivering air pressure from the control valve assembly to said power cylinder assembly.

3. In a portable fluid-driven actuator for a tool, the combination of: a body, a power cylinder assembly including a cylindrical shell, a cylindrical extension at one end of the body for connecting the body to the shell, support lugs at the other end of the body, means for releasably connecting said support lugs to a tool, the body having an axially extending central grip portion intermediate the cylindrical extension and support lugs shaped to be manually grasped by an operator whereby the actuator may be supported by one hand, a control valve assembly removably mounted on and forming a part of said grip portion of the body, the power cylinder assembly including a piston mounted for reciprocation within the shell and having a piston rod extending axially through the body, the control valve assembly including a movable valve element mounted within the outer surface of the grip portion and extending parallel to the piston rod, means for connecting the piston rod to actuate the tool, means for delivering a fluid under pressure to the control valve assembly, and passage means in the body for delivering fluid under pressure from the control valve assembly to said power cylinder assembly.

4. In a portable fluid-driven actuator for a tool, the combination of: a body, a power cylinder assembly including a cylindrical shell, a cylindrical extension at one end of the body for connecting the body to the shell, support elements at the other end of the body for connecting said body to a tool, the body having an axially extending central grip portion intermediate the cylindrical extension and support elements whereby the operator may support the actuator with one hand, a control valve assembly removably mounted on and forming a part of said grip portion of the body, said control valve assembly including a movable valve element adapted to be actuated by the same hand the power cylinder assembly including a piston mountedfor reciprocation within the shell and having a piston rod extending axially through the body to drive the tool, a fluid pressure inlet fitting fixed to an end of the power cylinder assembly remote from the body, means forming a passage for delivering a fluid under pressure from the inlet fitting to the control valve assembly, and the body having a passage for delivering fluid under pressure from the control valve assembly to said power cylinder assembly to drive the piston.

5. In a portable fluid-driven actuator for a tool, the combination of: a body, a power cylinder assembly including a cylindrical shell, a cylindrical extension at one end of the body for connecting the body to the shell,,support elements at the other end of the body for connecting said body to a tool, the body having a central portion intermediate the cylindrical extension and support elements, a control valve assembly removably mounted onsaid intermediate portion of the body, the power cylinder assem bly including a piston mounted for reciprocation within the shell and having a piston rod extending axially through the body to drive the tool, the piston rod having an axial opening therein, a stationary axial pressure supply tube on the power cylinder assembly forming a sliding seal with said piston rod opening, ports in the piston rod and "6 body establishing communication between the piston rod opening and the control valve assembly, and the body having a passage for delivering fluid under pressure from the control valve assembly to said power cylinder assembly to drive the piston.

6. In a fluid-driven actuator, the combination of: a cylinder, a member comprising a piston reciprocable in said cylinder and a piston rod secured to the piston, the member defining within the cylinder a forward chamber and a rear chamber, the member having an axial bore, an axial tube secured against axial movement relative to the cylinder and projecting into the rear chamber, an element fixed on the tube slidably received in the said axial bore and forming a seal therewith, means for delivering a fluid under pressure into said axial tube, the piston rod having a longitudinal passage communicating with said axial bore and having a lateral port therein, and means for delivering pressure fluid from said lateral port to said forward chamher and for venting said forward chamber to atmosphere.

7. In a fluid-driven actuator, the combination of: a cylinder, a member comprising a piston reciprocable in said cylinder and a piston rod secured to the piston, the member defining within the cylinder a forward chamber and a rear chamber, the member having an axial bore, an axial tube secured against axial movement relative to the cylinder and projecting into the rear chamber, an element fixed on the tube slidably received in the said axial bore and forming a seal therewith, means for delivering a fluid under pressure into said axial tube, the piston rod having a longitudinal passage communicating with said axial bore and having a lateral port therein, and means including a valve assembly secured relative to the cylinder for delivering pressure fluid from said lateral port to said forward chamber and for venting said forward chamber to atmosphere, whereby the piston is moved in one direction by pressure in the forward chamber and is moved in the other direction by the pressure in said axial bore.

8. In a fluid-driven actuator, the combination of: a primary cylinder, a member comprising a primary piston reciprocable in said primary cylinder and a piston rod secured to the primary piston, the member defining within the primary cylinder a forward chamber and a rear chamber, the member having an axial bore forming a secondary cylinder, an axial tube secured against axial movement relative to the primary cylinder and projecting axially into the rear chamber, a secondary piston fixed on'the tube slidably received in the secondary cylinder and forming a seal therewith, means for delivering a fluid under pressure into said axial tube, the piston rod having a longitudinal passage communicating with the secondary cylinder, means including valve means for delivering pres sure fluid from said longitudinal passage to said forward chamber and for venting said forward chamber to atmosphere, whereby the primary piston is moved in one direction by pressure in the forward chamber and is moved in the other direction by the pressure in said secondary cylinder.

9. In a fluid-driven actuator, the combination of: a relatively large cylinder, a member comprising a large piston reciprocable in said large cylinder and a piston rod secured to the large piston, the member defining within the large cylinder a forward chamber and a rear chamber, the member having an axial bore forming a small cylinder, an axial tube secured against axial movement relative to the large cylinder and projecting axially into the rear chamber, a small piston fixed on the tube slidably received in the small cylinder and forming a seal therewith, means for delivering a fluid under pressure into said axial tube, the piston rod having a longitudinal passage communicating with the small cylinder, means including valve means for delivering pressure fluid from said longitudinal passage to said forward chamber whereby the large piston is moved in one direction by pressure in the forward chamber while opposed by pressure in the smallcylinder, said means also acting to vent said forward chamber whereby the large piston is moved in the other direction by pressure in the small cylinder.

10. In a pneumatic actuator, the combination of: a power cylinder assembly, the assembly including a cylinder and a piston reciprocable in the cylinder and defining within the cylinder a forward chamber and a rear chamber, a hollow piston rod secured to the piston and extending through one end of the power cylinder assembly, the piston rod being closed at its extending end, axially extending telescoping parts on the piston 1 arid. cylinder for deliveringpressure fluid intoisaid'hdllow piston rod, "one of said "parts exten'dingtfinto "the" rear chamber, 'passage 'rneansincluding a: 'later'al portrin' the hollow" pi'ston"rod* for' deliveringpressure fluidfirom' the interior of the piston rod to said forward chan'abegwh'ereby"the jais'tonm'ay'bemoved in onedirectiomon ajpower strokerthetelescoping partsforn'iing asrnallergpiston and eylin'der assemblyconstantly acting to "movethefipiston in the other "direction,": whereby the pistoni'rnayfbe 1 returnedto its initial; "position upon "blocking of the 1 said passage means and ven'tin g of the" forward chamber.

1 1.1' In a; pneumatic actuator;theicombination of: a powericylinder assembly,- theias'sembly including a" cylinderarld 'apiston reciprocable in the'cylinder and defining Within the cylinder a" forward "charnberlarid a rear chamber," a"'hollow piston rod secured to the piston and extending, through one end of the power cylinder assemblyfithejp'is'tonrdd being'closed "at its extending .end, axiallylextendingtelescopic parts onfithe piston and cylinderfor'deliveringpressurefluid into said hollow piston rodfone er 'saidtparts extending .into l'the rear chamber, a control" valve assembly, passage means including a lateral port in thehollow piston rod'fforidelivering pressure"fluidffrom"the interior of the .piston' rod :to said control valve assembly,=.passage.means establishing .communication between 'thecontrol valve assembly. and .the forward. chamber, whereby the piston may be .moved in0ne. direction on apowerstroke, one'of .the telescoping pa'rtsIforming a smaller. piston and. cylinder assem-.

blyconstantly' acting to..move the piston=in" the other 'direction, .wher'ebythe piston. mayxbe returned to its initial positionrupon blockingof-lthe saidpassage means and venting of the forward .ichamber.

12.7:In-a.pneumatic .actuator, the combination of: a power. cylinder. assembly, the :assembly including. a cylinde'r and apiston reciprocable inthe cylinder: andId'efining withinthe cylinder. aforwa'rdfchamberand a rearchamber,. a hollow..pistonrod securedto the. piston. and extendingithrought-one end of "the power cylindernassernbly, .the piston rod .being-aclosed at its :extending end, an. axially immovabletube extending axially into the rear chamber fromthe other end of the powerlcylirider assembly,-.anzelementzlfixed .onthetube received within the hollow piston rod i and 'forming :a seal .therewith, meansfor. delivering pressure fluid into said tube and passage means including a lateral'port inrthe-hollow piston rod for-del-ivering-pressure fluid-from the-interior of the piston rodtozsaid. forward chamber.

13.. In -a pneumatic-actuator, thelcombination of: a power cylinder assembly,- the: assembly including a: cylinder-t and a r piston.reciprocablenin the: cylinderi-and defining -w-ithin. the cylinder a forward chamber and :a rearichamber, a hollow. piston rod secured to the piston and extending through 1 one end of E'the power cylinder assembly, the-piston -rod-being closed atwits extending end, an axially immovable tube extending axially into the Tear-chamber fromthe-other =end ofthe power. cylinder: assembly,t..anelement. fixed on .the tube received Withimthehollow-pistorrrod. andiforrning a seal therewith I-means-for delivering pressure fluid into said tube, a t-control valve assembly fixed-relative to the. cylinder, means-including a wlateralport in. the: hollow piston rod for'delivering pressure fluid from the interior ofithe piston. rod: to said. control valve assembly, and passage meanswstablishing communication between the control valve-assemblyand' theforward chamber.

- 14: In a pneumatic-actuator, the combination of: a poWeficvli-ndenassembly, the-assembly including a cylinder having an enddclosure, the assembly also'including apiston reciprocable in the-"cvlinderand defining'within the cylinderaforward chamber'and. a rear chamber, a hollo'w piston rod member-securedto .the piston and extending throuah rthe"forward'end' of the power cylindemassembly; the piston'rod 'beingi closed 'fat itsextend.

ing end, an axially im'movable tube' 'rnember 1 extending axiallyinto the rear chamber throughsaidend:closure, an element fixd 'on the tube m'ernberand' received within""the hollow piston1--rod- -member to form a-sliding s'e'al therewith, *means for delivering; pressure fluid-into said tube rmer'nber, 'means" including, a ateral port *in "therhbllowi'piston rod for'delivering "pressure fluid' from the *inte'rior 'of the, piston rod-to said torward charnherywherebyjiithe piston 'may be'moved vin one'idirection {on 'a power" stroke, and an annulafdistort'able bumper carried" e upon the end'"closure encircling the stationary tube-and engagedby the pistonat theeiid bf itspower'strbke;

1:15 'Irra d'evicezofithe classdescribed; abodypa power cylindera'ss'embly secure to=:the-body at*one""end,':"a central"openingcxtending taxially through -the bodyrthe power cylinder assemblyinbhiding a'rcciprocablepiston, a piston rod secured 'tothe pistoniand' extending through said'central' opening in. the body,f"n1eans-for delivering atffluid "underpressure-into said; powenc'ylinder assembly 'to' move the pistoirraxially, 'said'means including a unitary control valve'a'ssembly, said assembly including an axially extendinghousing *havingza longitudinallyextending'r'side surface, the"body*havinga"complernentary axiallyextending side surface to receive the" housingg' the body and housing? cooperating to provide a-ha1idle .grip which maybe 'grasped' manually 'in one hand for supportingthef device, means'tor detachably" securing the? housing onthe body with saidhousing surface'and .body'face inimutual contact, :a plurality of ports in"'the.*hou'sing extending .to said 'flat'surface, apluralityof corresponding ports in 'the body extendingto-said face andeach'aligned withone of said housing ports; a'movable-valve element mounted within "said housing, .a"valve"operating"lever movably mounted on .the "housing: "at a. location remote from said power cylinder 'for actuating the valve element, passage means including Lone aof said pair t'of alignedports' fordeliveringfluid under pressurez'fronrthe controlvalve assembly to the power cylinder assembly, and passage'rneansincluding another pair'of aligned ports forven'tingthe 'power cylinderassembly to atmosphere.

716.1 In a device of'the class described; a body,1a power cylinder assembly-jsecuredto' thebody atone end,'.a 'cen tral opening extending axially through'the body,' the power; cylinder assembly including a reciprocablepiston, a'piston' rod secured to "the'piston and extendingthrough said'centralopening in 'the"body,means-'for delivering a fluid under pressure "intosaid power cylinder assembly to 'move 'the piston. axially, said means including a unitary control valve assembly, 'said' assembly'includingqan ment, passagemeans including one of said pair ofraligned ports-i01 delivering fluideunder pressure fromzithe ..control valve. assembly .to the power! cylinder. assembly, and passage 7 means including another: pair. of aligned -ports for venting the poweix cylinder assemblyto atmosphere.

l7. In -a; portableifiuid-drivenactuator for attool, the combination of:- a body, a power cylinder assembly connected to one endrofwthe body, means at the. otherrend of-tthebodyt forrconnectingw said body to a tool ethe body= having an axially: extending centralportion. intermediate: at. its zends shaped to" be manually tgraspe'd bygan operator whereby the actuator may be supported-by: one hand, a: control valve. assembly mounted onsaid "intermediate portion'of the body and having a part manually operable by the same hand, the power cylinder assembly including azpiston rod extending axially through :1116 body for operating the tool, a fiuid: inletr'fitting'mounted centrally: on nan end of the power'cylinder assembly remote'zfrom'ithei body," passage means extending centrally of' the power cylinder assembly for. delivering fluid EIfIOIH the inl'et'fitting" to the control: valve assembly, and means for delivering fluid from 'the' control"valveassembly to the power cylinder assembly.

l8. Ina portable fluid-drivenactuator foraitooL the combination of: a'body, a power cylinder assembly including a cylindrical shell a cylindrical extensionfat one end-of the body for connecting the body to the shell, support elements at the other end of the body for 'connecting said body'to a tool, the body having an. axially extending central vgrip portion intermediate 'the cylindrical" extension: and support elements whereby the operator may support the actuator with" onehand, a control= valve assembly removably mounted on and forming a part of said grip portion of the body, said control valve assembly including a movable valve element adapted to be actuated by the same hand, the power cylinder assembly including a piston mounted for reciprocation within the shell and having a piston rod extending axially through the body to drive the tool, a fluid pressure inlet fitting fixed to an end of the power cylinder assembly remote from the body, means forming a passage extending centrally of the shell and piston for delivering a fluid under pressure from the inlet fitting to the control valve assembly, and the body having a passage for delivering fluid under pressure from the control valve assembly to said power cylinder assembly to drive the piston.

Reference! Cited in the tile of this patent UNITED STATES PATENTS 465,008 Weather-son Dec. 15, 1891 10 Davidson June 29, 1909 Osbourne July 29, 1924 Campbell May 26, 1931 Osborne Apr. 5, 1938 Bragg Mar. 4, 1941 Fischer et a1 Aug. 8, 1944 Johnson Jan. 9, 1945 Carlson June 14, 1949 Mothorn Nov. 15, 1949 Potstada Ian. 3, 1950 Holowka Feb. 27, 1951 FOREIGN PATENTS France July 10, 1920 France May 26, 1930 

